A Cortnee Vine double has helped secure Sydney FC a dramatic 4-2 extra-time win over Melbourne City and passage to a fifth consecutive grand final.

A double from Hannah Wilkinson had Melbourne City in charge before substitute Vine pulled a goal back and Maria Jose Rojas sent a torrid contest into 30 added minutes.

Rojas's goal completed a momentum-shifting few minutes with City's TJ Vlajnic sent off for a foul on Vine.

Teenage substitute Sarah Hunter gave the home side the lead six minutes into extra-time and Vine bagged another to end the scoring at Kogarah's Jubilee Stadium.

City's night went from bad to worse in the dying stages with veteran goalkeeper Melissa Barbieri dismissed after handling the ball outside the penalty area.

Sydney FC had made history last Sunday when it topped the ladder for a record-breaking fourth time after finishing two points clear of their opponents.

The Sky Blues were presented with the Premiers Plate prior to kick-off against City, who will have another opportunity to feature in the decider thanks to the league's new finals format.

City now face the winner of Sunday's elimination semifinal between Adelaide United and the visiting Melbourne Victory.

Sydney FC will host the season decider in a fortnight.

City failed to breach the Sky Blues' penalty area during the first 20 minutes until Vlajnic produced a flying save from goalkeeper Jada Mathyssen-Whyman.

A minute later City had the all-important opener when the league's top scorer Wilkinson profited from captain Natalie Tobin's uncharacteristic defensive error and was left with an easy finish past an exposed Mathyssen-Whyman.

The half-time introduction of Vine added spark, but a City side who have won all of their eight A-League Women finals matches rarely looked like being exposed.

The contest seemed over when New Zealand international Wilkinson doubled the advantage 13 minutes after the break with a perfect near-post finish, following strong lead-up work from Leticia McKenna and Rebekah Stott.

Vine's powerful headed goal on 73 minutes pulled the home side back into the contest after Ally Green's powerful run set up the opportunity.

The goal saw momentum swing the way of the Sky Blues and Vine pinged an effort off the top of the crossbar.

Vine looked set to score when she rounded goalkeeper Barbieri in the final minutes only to be bundled over by Vlajnic who was dismissed for the last-player foul.

Substitute Rojas fired home a loose ball a minute into the five minutes of added time.

Eighteen-year-old Hunter powered home a close-range header and Vine extended the winning margin with seven minutes left.

AAP